In the treatment of joint stiffness or contractures which decrease the range of motion of the joint, an orthotic device may be used to urge the joint in a desired direction for providing exercise for improving the range of motion of the joint. For example, to treat an elbow flexion contracture, it may be desirable to urge the arm to extend. Conversely, to treat an elbow extension contracture, it may be desirable to urge the arm to flex. Known orthotic devices typically utilize a spring or a jack screw to bias the joint and are often suitable only for flexion or extension, or are cumbersome to use.
The present invention relates to orthotic devices of improved construction. The orthotic devices described herein are selectively configurable for assisting a joint to flex or to extend and do not utilize a spring, thus offering advantages over prior devices which can only be used for extension or flexion or which utilize a spring for applying force to a joint.
In a preferred embodiment, the orthotic devices include a first limb engaging assembly; a second limb engaging assembly; and a gear assembly linking the first and second limb engaging assemblies and operable to assist in either flexion or extension of the joint of the limb of the patient.
The gear assembly preferably includes first and second mounting arms pivotally mountable relative to one another, with the first mounting arm connected to the first limb engaging assembly and the second mounting arm connected to the second limb engaging assembly. A threaded shaft is rotatably mounted on a mount and the mount is pivotally connected to the first mounting arm. A toothed gear is rotatably mounted to the first mounting arm and fixedly mounted to the second mounting arm.
The mount may be pivotally moved to engage the threaded shaft with the toothed gear and the threaded shaft rotated to rotate the toothed gear and change the position of the second mounting arm relative to the first mounting arm.